Internal-combustion engine



May 8, 1945. T. R. ARDEN INTERNAL-COMBUSTION ENGINE Filed Feb. 27, 1942 2 Sheets-Sheet l- May 9 T. R. ARDEN 2,375,183

INTERNAL-COMBUSTION ENGINE Filed Feb. 27, 1942 2 Sheets-Sheet 2 bvrEn Twe mums R./7rden;, 5

ay recs Patented I 2,375,183 INTERNAL-COMBUSTION ENGINE Thomas R. Arden. Danbury, @onm, asslgnor to I Bard-Parker Company,

a corporation of New York Application Febmary2'l, 1942, Serial No. 432,709 7 Claims. ((31. 123-48) This invention relates to internal combustionengines, and has particular reference to selfignition internalcombustion engines of the type disclosed in my prior application, Serial No. 278,- 772, filed June 12, 1939 (now Patent No. 2,274,644,

dated March 3, 1942), of which the present application is, in part, a continuation.

Generally speaking, the object of the invention is to provide an'internal combustion engine embodying a practical construction whereby the same may be successfully operated at various difierent speeds within a wide range, and .whereby its speed may quickly be accelerated and decelerated, and which may even be started, without fuel injection such as characterizes internal combustion engines of the Diesel type, and also without spark ignition such as characterizes ordinary internal combustion engines employing gasoline as fuel.

With the foregoing and other objects in view, which will become more fully apparent as the natureof the invention is better understood, the

same consists in a self-ignition internal combus-' tion e'ngine embodying the novel features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings and defined in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in related views:

Figure 1 is a side elevation of a portion of a self-, ignition internal combustion engine constructed in accordance with one practical embodiment of the invention.

Figure 2 is a central, vertical section through the engine structure shown in Fig. 1.

Figure 3 is a horizontal section on the line 3-3 of Fig. 2; and u Figure 4 is a view similar to Fig. 2 illustrating an alternative form of the invention.

It is known that an internal combustion engine whose proportions are designed correctly, ac-' cording to known standards, will function without spark ignition and without fuel injection, such as characterizes engines of the Diesel type,

when the compression, speed, temperature andother factors are brought to a critical point, and the present invention resides in means for attaining and maintaining this critical point for any given speed of operation ofan engine, and for quickly varying such point in accordance with desired changes in the speed of the engine, whereby the aforesaid general object of the invention is accomplished.

Ina, Danbilry, Conn,

Referring to the. drawings in detail, first with particular reference to the embodiment of the invention illustrated in Figs. 1 to 3, it will be ole-- served that the present engine is hf the reciprocating type and includes, as usual, a crank case in, a crank shaft It, a cylinder ii a piston til reciprocable within the cylinder M and a connecting rod 2s providing an operative connection between the piston l3 and the crank shaft M whereby reciprocating motion of said piston is translated into rotary motion of said crank shaft.

It will further be observed that the engine illustrated in Figs. 1 to 3 is of the two-stroke-cycle type in which the cylinder H is provided with exhaust ports 3| to be uncovered by the piston I3 as the latter nears the end of its inward or power stroke, and in which fuel is delivered from the crank case H) to the cylinder H through a port 26 in the outer end f the piston w under v the control of a valve 21 at the .outer end of a sleeve'23 which is reciprocable within the piston I3 and through the instrumentality of which,

said piston is operatively connected with the crank shaft it by the rod M an as more fully described in my aforesaid Patent No. 2,274,644. However, it is desired to point out in this connection that. the improvements constituting the present invention are equally capable of use either in association with four-stroke-cycle engines or in association with two-stroke-cycle engines having means other than the means herein illustrated and described for controlling admission of fuel to and exhaust of products of combustion from the cylinder II. In other words, the improvements constituting the present invention reside essentially in the provision of a cylinder head which is movable longitudinally with respect tothe cylinderto vary the capacity of thecombustion chamber of the engine; which is resiliently urged inwardly so as to be capable of moving outwardly under the force of a charge of fuel exploding in the combustion chamber, and which has associated therewith adjustable means for variably predetermining its innermost position. These essentials may be embodied in practically any internal combustion engine of the reciprocating piston type regardless of the number of strokes per cycle of the engine and regardless of the particular means employed to control .admission of fuel to and exhaust'of products of combustion from the engine. Accordingly, it will be understood that,,apar t from these essentials, the engine may be of any construction and may have any usual mode of operation except as afiected by the said improvements.

In accordance with the invention as in Figs. 1 to 3, the cylinder II" has mounted in its outer end, for. longitudinal sliding movement relative to said cylinder to vary the capacity or the combustion chamber a, a cylinder head designated as I04. Thishead'is of caplike form, closed at its inner end and open at its outer end and, at its outer end is provided with an annular, outwardly extending flange I05 which is disposed within a counter-bore I06 in an enlarged extreme outer end portion Il'of the cylinder I I.

Threaded on the outer end portion I01 of the cylinder II is a capvmember l08 and between this cap member and the cylinder head I04 is interposed a coil spring I09 which urges the cylinder head constantly inwardly.

Disposed in the counterbore I06 of the cylinder H in surrounding relationship to the cvlin-' der head I04 and interposed between the flange I and the wall defining the bottom of said counterbore is a ring IIO which is rotatably adjustableandwhich has its inner edge formed with a series of inclined cam faces III for cooperation with a companion series of cam faces' II2 formed on the wall defining the inner end of the counterbore I06. l The ring H0 constitutes a stop engageable by the flange I05 of the cylinder head I04 to limit inward movement of the cylinder head. By rotating the ring H0 in one direction it will be moved outwardly due to the cooperation of its cam faces I with the cam faces H2 and will move the cylinder head outwardly. 0n the other hand, by rotating said ring in the opposite direction, inward movement of the cylinder head by the spring I09will be permitted. Rotation of the ring IIO may be efiected in any suitable manner. In the present instance there is illustrated for this purpose a means in the form of a handle II3 projecting laterally from said ring through a slot H4 in the outer endportion I0I of the cylinder II; In anyevent, by rotatable adjustment of the ring IIO the inner limitof illustratedchamber of the engine would prevent furtherbustion chamber, and since the time at which ignition takes place in large measure determines the speed of the engine, it is apparent that, by rotating the ring H0 to vary the area of the combustion chamber of the engine, the speed of operatlon of theengine under self-ignition may be varied within a wide range. This would not be possible if the cylinder head were positively restrained against outward movement, for in that case, if ignition occurred prior to the piston i3 reaching a definite position short of its outermost position, explosion of a charge in the 'combustion outward movement of the piston. Due, however, to the cylinder head I04 being yieldably restrained against outward movement, it may yield outwardly under the force of an explosion in the com-, bustion chamber to relieve the'pressure therein and permit outward movement of the piston to continue even though ignition may occur at an early instant during outward movement of the piston. Outward movement or the cylinder head stores in. the spring I09 energy which subsequently is expended'in assisting to drive the piston inwardly. By the selection of a spring I00 of a certain inherent strength and by proper adjustment of the same by the cap piece I08 in movement of the cylinder head I04 may variably be predetermined to variably predetermine the normal capacity of the combustion chamber of the engine.

The force exerted inwardly upon the cylinder head I04 by the sprin I09 may be varied by ro- 'tating the cap member I08 to thread same in-' wardly or' outwardly along the portion I0! of the cylinder. Inany event, the strength of the spring I09 at all times is sufficient to prevent outward movement of the cylinder head under self-ignition pressure in the combustion chamber ofrthe engine. The strength of said spring is not'so great, however, as to prevent outward movement of the cylinder head under the force ofanjexploded charge in the cylinder.

Rijeierably the engine is provided with a sparkplugf'32 whereby it may be started using spark ignition. 'lf'referably, too, a heat retaining element H5 is provided in the combustion chamber of the engine to assist self-ignition. However, neither said spark-plug nor said element H5 is essential, as the engine may be started by selfignition' and will operate without the element Sincevarying the area of the, combustion chamber of the engine determines the time at which, during outward movement of the piston 23, self-ignition pressure will develop in thecomrelation to different adjustments of the innermost limit of movement of the cylinder head, the engine may be made to opera'tesuccessfully within a wide speed range, and may, even be started, employing self-ignition as distinguished from spark ignition. Such an engine is particularly advantageous in eliminating all spark ignition mechanism and, as a power plant for miniature aircraft,- is further particularly advantageous in that it eliminates the necessity of the aircraft carrying a weighty battery to furnish current for spark ignition. f

Referring now to the embodiment of the invention illustrated in Fig. 4 of the drawings, it will be observed that the construction and-mode of operation of the means constituting the invention is generally the same as the. means illustrated in Figs. 1 to 3, except that air pressure instead of a spring is employed primarily to restrain the cylinder head against outward movement during operation of the engine.

In accordance with the embodiment of the invention illustrated in Fig. 4, the engine cylinder, designated as H, has mounted in its outer end, for'longitudinal sliding movement relative thereto, as in'the case of the Figs. 1 to 3 embodiment of the invention, a cup-shaped head, designated as I04 which is provided at its outer end with an annular; outwardly extending flange I05 disposed within a counterbore I06 in the outer end of the cylinder II. Moreover, the-wall I04 defining the inner end of the cylinder head I04 has located preferably centrally thereof and extending outwardly therefrom a hollow pump piston I20 in the inner end portion of which are ports I20 providing communication between its interior and the interior of said cylinder head I04 and in the outer end-of which is a plug I2I having a port 122 controlled by an inwardly openingcheck valve I23 of any suitable type which normally is urged outwardly against said seat in closing relationship to said port by a coil spring I24 interposed between said valve and the inner end wall I04 ofthe cylinder head I04".

7 Suitably secured to the outer end of the cylinder II, as by means of screws I25, is a cap member I26 which has extending inwardly therefrom into and closely fitting the cylinder head I 2,375,183 I 04'' a cylindrical'skirt portion I21, while inter- The cap member I 26 carries, preferably centrally thereof, an inwardly extending pump cylinder I29 into the inner end portion of which the pump piston I20 slidably extends.

Threadedin the outer end portion of the pump cylinder I29 for longitudinal adjustment relative thereto is a plug I30 having a port I3I openingto the atmosphere and also having a valve seat I32 with which cooperates an inwardly opening check valve I33 of any suitable type controlling communication between the interior of the pump cylinder I29 and the atmosphere through said port, said valve I33 being normally urged outwardly against its seat I32 in closing relationship to the port I3I by a coil spring I 34 interposed between said valve and a suitable abutment such as a plug I35 threaded in the inner end portion 7 of the plug I30 and having a port I36 therein providing communication between the cylinder I29 and the port I3I under the control of said valve I33.

As in the case of the embodiment of the invention illustrated in Figs. 1 to 3, the Fig. 4 embodiment of the invention includes a rotatably adjustable cam ring III] disposed in the counterbore Iflfi of the cylinder Il between the wall defining the inner end of said counterbore and the flange I of the cylinder head I04 and provided at its inner edge with a series of inclined cam faces III for cooperation with a companion series of cam faces II2 on the said wall defining the inner end of the counterbore I 06* to variably predetermine thelimit of inward movement of the cylinder head I04.

In accordance with the Fig. 4 embodiment of the invention the spring I28 is only of sufilcient strength normally to hold the cylinder head I03 at its limit of inward movement when theengine is not operating, the force to restrain said cylinder head against outward movement when the engine is operating being obtained by airpressure developed in the space b between thecap member I26 and the cylinder head IIl I as a result of outward movement of said cylinder-by of this space may be varied by adjusting the plug I inwardly or outwardly. Accordingly, by adjustment of said plug I30 the air pressure within the space b may-be regulated so that the force .exerted inwardly on the cylinder head IIlIt is greater than the fuel compression pressure developed in the combustion chamber a by outward movement of the engine piston I3, but is not as great as the forceaexerted outwardly upon said cylinder head by explosion of a charge of fuel in the combustion chamber a. a

To start the engine following a proper adjustment of the plug I30, the cam ring IIII is adjusted to permit the cylinder head to be moved by the spring I28 to its innermost limit of movement, The engine then is turned over a number of times manually or by a starter until there is built up in the space 17 an air pressure sufficient to resist outward movement of the cylinder head under a fuel compression pressure such as will produce self-ignition of the fuel charge, whereupon the engine will start.

Since varying of the size of the combustion chamber a, of the engine determines the time at which, during outward movement of the engine piston I3 self-ignition pressure (heat due to rapid compression) will occur in said combustion chamber a, and since. the time at which selfignition occurs in a large measure determines the speed of the engine, it is obvious that the engine speed may be varied over a wide range and quickly by adjustment of the cam ring I III to vary the innermost limit of movement of the cylinder head I64 and to thereby vary the size of the combustion chamber a. embodiment of the invention has the same mode of operation and the advantages of the Figs. 1 to 3 embodiment of the invention, except that primarily air pressure rather than a spring is employed to resiliently restrain the cylinder head against outward movement and to produce inward movement thereof.

inner end portion of the pump cylinder I23 and, p by outward movement of said cylinder head, to

force air from the inner end portion of said-- pump cylinder I 29 through the port I22, the pump. piston-I20 and the ports I20 into the space'b between said cylinder head and the cap I26.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor' details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

I claim:

' 1. A self-ignition internal combustion engine comprising a cylinder, a piston reciprocable therein, a member inwardly movable relative to said cylinder to decrease the space of the combustion chamber of the engine, a cam ring surrounding said member and operative by rotative adjustments thereof to predetermine the limit of inward movement of said member, and resilient means resisting outward'movement of said memher, said resilient means having suflicient strength When the engine is operating, explosions in the combustion chamber a force the cylinder head Int outwardly, but when exhaust occurs and pressure in said combustion chamber a is relieved, the spring I28 in conjunction with air pressurein the space b force said cylinder head inwardly. Accordingly, during operation of the engine the pump mechanism described will tend constantly to pump air into the space b and to create a certain air pressure therein dependent upon the capacity of the pump space between the valves I23 and I33. Obviously, the capacity to hold said member against outward movement under a fuel compression pressure in the combustion chamber such as will cause self-ignition of the fuel and having insuflicient strength to hold said member against outward movement under the pressure developed in the combustion chamher by explosion of a fuel charge therein.

2. A self-ignition internal combustion engine comprising a cylinder, a piston reciprocable therein, a cylinder head mounted in the outer end portion of said cylinder for inward and outward sliding movement relative thereto to vary the size of the' combustion chamber of the engine, a cam ring surrounding said cylinder head and In short, the Fig. 4

interposed between a portion thereof and a portion of said cylinder and operative by rotative adjustment thereof to p'redetermine the limit of inward movement of said cylinder head, and reoutward movement under the pressure developed in the combustion chamber by xplosion of a fuel charge therein.

3. A self-ignition internal combustion engine comprising a cylinder having outwardly facing cam formations adjacent to its outer end, a piston reciprocable in said cylinder, a cylinder head mounted in the outer end portion of said cylinder for inward and outward sliding movement relative thereto to vary the size of the 'combustion chamber of the engine, said cylinder head having an inwardly facing shoulder, a rotatably adjustable ring surrounding said cylinder head between said shoulder and the cam formations of the cylinder and serving as a stop to limit inward movement of said cylinder'head, said ring having cam formations for cooperation with the said cam formations of the cylinder to efiect longitudinal adjustment of said ring inresponse to rotary adjustment thereof to predetermi'ne the limit of inward movement of the cylinder head, and resilient means resisting outwardmovement of said cylinder head, said resilient means having sumcient strength to hold saidcylinder head against outward'movement under a fuel compression pressure in the combustion chamber that will cause self-ignition of the fuel and having insuflicient strength to hold said cylinder head against outward movement under the pressure developed in the combustion chamber by explosion of a fuel charge therein.

4. A self-ignition internal combustion engine comprising a cylinder, 9. piston reciprocable therein, a member movable inwardly and outwardly relative to said cylinder tovary the size cient to hold said member against outward movement under a fuel compression pressure in the combustion chamber that will cause self-ignition of the fuel and insuflicient to hold said member against outward movement under the pressure developed in the combustion chamber by explosion of a fuel charge therein. 5. A self-ignition internal combustion engin as set forth in claim 4 in which the means for supplyingto'and maintaining in the air chamber air under pressure comprises an air pump operable by inward and outward movement of the member for varying the size of the engine coinbustion chamber. 6. A self-ignition internal combustion engine as set forth in claim 4 in which the means for of the combustion chamber of the engine, means adjustable to predetermine the limit of inward movement of said member, means cooperating with said member to define. an air chamber out- .wardly of said member and of which said member constitutes at least a portion of the inner wall,

whereby said member is urged inwardly when said chamber is supplied with air under pressure, and means for supplying said chamber with and for maintaining therein air under a pressure suflisupplying to and maintaining in the air chamber air under pressure comprises an air pump operable by inward and outward movement' of the member for varying the size of the engine combustion chamber, and means adjustable to regulate the pumping action of said air pump in relation to the amount of inward and outward movement of said member to maintain the air in said chamber within a pressure'range to accomplish I the purposes stated. i g

7. A self-ignition internal combustion engine comprising a, cylinder, 2. piston reoiprocable therein, a cylinder head mounted in the outer end portion of said cylinder for inward and outward movement relative thereto to vary the size of the combustion chamber of the engine, means adjustable to predetermine the limit of inward movement of said cylinder head, a cap member carried by the cylinder and cooperating with said cylinder head'to provide an air chamber of which said cylinder-head comprises the inner wall, an air pump for supplying air to said chamber, said pump comprising a cylinder and a cooperating piston one of which is carried by said cylinder head and the other by said cap member so that said pump is operable by inward and outward movement of said cylinder head, and means for regulating the action of said pump in relation to the movement of said cylinder head so that duririg operation of the engine air in said air chamber is maintained under a pressure sufllcient to hold said cylinder head against outward move THOMAS R. ARDEN. 

